Accrual balance with different start dates for plans

Summary:

my customer is an international company and the various countries have different accrual plans. For most countries the plans start at January 1th of a year, but for some (France) the plan start at June 1th or a specific BU at July 1th

When I create a dashboard or report showing balances per worker I can see the annual accrual, correct figure, but days taken are for the entire year, meaning including days taken before start day of a plan.

Any suggestion how to make the figures for these kind of plans appear correct?

Version (include the version you are using, if applicable):